Is transverse screw fixation really necessary in PAO?—A comparative in vivo study

Abstract

The optimal fixation technique in periacetabular osteotomy (PAO) remains controversial. This study aims to assess the in vivo stability of fixation in PAO with and without the use of a transverse screw. We performed a retrospective study to analyse consecutive patients who underwent PAO between January 2015 and June 2017. Eighty four patients (93 hips) of which 79% were female were included. In 54 cases, no transverse screw was used (group 1) compared with 39 with transverse screw (group 2). Mean age was 26.5 (15–44) in group 1 and 28.4 (16–45) in group 2. Radiological parameters relevant for DDH including lateral center edge angle of Wiberg (LCEA), Tönnis angle (TA) and femoral head extrusion index (FHEI) were measured preoperatively, post-operatively and at 3-months follow-up. All patients were mobilized with the same mobilization regimen. Post-operative LCEA, TA and FHEI were improved significantly in both groups for all parameters (P ≤ 0.0001). Mean initial correction for LCEA (P = 0.753), TA (P = 0.083) and FHEI (P = 0.616) showed no significant difference between the groups. Final correction at follow-up of the respective parameters was also not significantly different between both groups for LCEA (P = 0.447), TA (P = 0.100) and FHEI (P = 0.270). There was no significant difference between initial and final correction for the respective parameters. Accordingly, only minimal loss of correction was measured, showing no difference between the two groups for LCEA (P = 0.227), TA (P = 0.153) and FHEI (P = 0.324). Transverse screw fixation is not associated with increased fragment stability in PAO. This can be taken into account by surgeons when deciding on the fixation technique of the acetabular fragment in PAO.

Mechanical upside of PAO mainstream fixations: co-simulation based on early postoperative gait characteristics of DDH patients

“…During the surgery, intraoperative osteotomy requires internal fixation to maintain stabilization of the acetabular fragment. The IS and TS internal fixation techniques are the mainstream approaches used in PAO, and various clinical and mechanical studies, ranging from in vitro experiments to simulations, have been reported ( Babis et al, 2002 ; Yassir et al, 2005 ; Mechlenburg et al, 2007 ; Widmer et al, 2010 ; Bakhtiarinejad et al, 2021 ; Leopold et al, 2021 ). However, those mechanical research studies were limited due to the lack of realistic gait simulation, and muscle force that should contribute to the deformation and stress of the bone was not represented in models, leading to underreported FE results ( Chen et al, 2019 ).…”

“…However, the fixation of the reorientation acetabular fragment remains a challenge. It has also been shown to have some postoperative complications such as the non-union of one of the osteotomies and stress fracture, which may be related to the internal fixation ( Malviya et al, 2015 ; Leopold et al, 2021 ; Morris et al, 2022 ). However, two common screw internal fixation techniques have been reported: 1) iliac screw (IS) fixation, in which three cortical screws of different lengths are inserted from the iliac crest into the acetabular fragment, and 2) transverse screw (TS) fixation, in which two cortical screws are inserted from the iliac crest into the acetabular fragment, and then, an additional cortical screw is inserted transversely from the acetabular fragment into the ilium.…”

Periacetabular Osteotomy and Postoperative Pregnancy—Is There an Influence on the Mode of Birth?

“…As one of the surgical techniques performed in the treatment of DDH, periacetabular osteotomy (PAO) allows for a three-dimensional reorientation of the hip socket to provide improved coverage of the femoral head. This is achieved by completely detaching the acetabulum from the pelvis through defined osteotomies along the Os ischium, Os pubis and Os ilium before fixing the acetabular fragment either with K-wires or screws [ 4 , 5 , 6 , 7 ]. In contrast to other pelvic osteotomies, the posterior column remains intact [ 4 ].…”